We use the boost invariant version of the hydrodynamic model MUSIC [1]} for Pb+Pb collisions at \(5.02\)  TeV. For the initial state, two models are used; a two-component Glauber Monte Carlo model [2]} and the TRENTO model [3]}. We use a constant shear viscosity to entropy density ratio \(\eta /s=0.08\) , unless otherwise specified.
In Fig. REF  are shown the factorization breaking coefficients between the flow vectors squared (left) and flow magnitudes squared (right) for the elliptic flow. For 0-5 % centrality our model result corroborate the ALICE preliminary data. However, for semi-central collision (30-40 %), our model results do not fully describe the data. Also one can see that the decorrelation for the magnitudes \(r_2^{v_2^2}(p)\) , is approximately one half of the decorrelation for the vectors \(r_{2 ;2} ( p)\)  in REF , which manifest the fact that the total flow vector decorrelation involves equal contribution from the flow magnitude and the flow angle decorrelation; \([1-r_{n;2}(p)]\simeq 2 [1-r_n^{v_n^2}(p)]\) .
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